Items
Items are implemented through the items db table. A item represents some content (tasks, chapter, …) and are structured (acyclic graph) via the items_items table, the ancestors hierarchy is cached in items_ancestors.
The type of an item (his type attribute) is important to know the actions which are possible on it and which attributes are relevant. The following table compares the main differences:
| “Chapter” | “Task” | “Course” | “Skill” | |
|---|---|---|---|---|
| Main usage | Container for tasks and course | Exercice to be solved to get a score | Content to be read | Skill to be obtained by solving tasks |
| Have children items | Tasks and courses | No | No | Chapters (with warning), tasks, courses and skills |
| Attempts have answers | No | Yes | No | No |
| Attempts have a score | Through propagation from children (content computation) | Through submitted answers | Never | Through propagation (skill computation) |
| Relevant dates for attempts | started_at, validated_at, latest_activity_at | started_at, validated_at, latest_activity_at, score_obtained_at, latest_answer_at, latest_hint_at | started_at, latest_activity_at | started_at , validated_at, latest_activity_at (not sure) |
| Can have several attempts | Currently no (later Yes) | Yes | No | No |
| Can be unlocked by other items | Yes | Yes | Yes | Yes |
| Can have prerequisites | ? | ? | ? | Yes |